Daily Respiratory Research Analysis
Three high-impact studies in respiratory medicine span interventional cardiopulmonary care, infectious disease prevention, and antimicrobial stewardship. A nationwide Japanese registry shows balloon pulmonary angioplasty (BPA) delivers robust hemodynamic benefits with low periprocedural mortality across hospital volumes, though severe complications are fewer in high-volume centers. Modeling from Latin America and the Caribbean optimizes timing of RSV passive immunization, while a multicenter ana
Summary
Three high-impact studies in respiratory medicine span interventional cardiopulmonary care, infectious disease prevention, and antimicrobial stewardship. A nationwide Japanese registry shows balloon pulmonary angioplasty (BPA) delivers robust hemodynamic benefits with low periprocedural mortality across hospital volumes, though severe complications are fewer in high-volume centers. Modeling from Latin America and the Caribbean optimizes timing of RSV passive immunization, while a multicenter analysis links higher cumulative corticosteroid dosing in non-HIV Pneumocystis pneumonia to increased mortality without respiratory benefit.
Research Themes
- Pulmonary vascular interventions and health system volume–outcome relationships
- Seasonality-informed prevention strategies for pediatric RSV
- Risk–benefit reassessment of adjunctive corticosteroids in opportunistic pneumonia
Selected Articles
1. Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension: A Nationwide Prospective Multicenter Registry in Japan (J-BPA).
In this nationwide, prospective registry of 1202 CTEPH patients undergoing 5207 BPA procedures across 44 hospitals, BPA substantially improved hemodynamics (55.6% PVR reduction) with 0.2% periprocedural mortality. Efficacy and mortality were comparable between low- and high-volume centers, but severe complications were significantly less frequent in high-volume hospitals.
Impact: This is the largest prospective assessment of contemporary BPA across a national health system, demonstrating broad reproducibility with strong safety signals that are volume-dependent for severe complications.
Clinical Implications: BPA can be safely expanded beyond expert centers with comparable efficacy and very low periprocedural mortality; however, complex cases and training should be concentrated in high-volume centers to minimize severe complications.
Key Findings
- Among 1202 patients (44 hospitals), BPA reduced pulmonary vascular resistance by 55.6% with 0.2% periprocedural mortality.
- Low-volume hospitals conducted 40.8% of procedures; efficacy and periprocedural mortality did not differ by volume.
- Severe complications were significantly less frequent in high-volume hospitals (severe lung injury 0.3% vs 1.3%; balloon overdilatation 0.67% vs 1.7%; ventilation 0.3% vs 1.5%).
Methodological Strengths
- Prospective nationwide multicenter registry with large sample size (n=1202) and 5207 procedures
- Predefined volume categories aligned with international consensus (WSPH) enabling meaningful comparisons
Limitations
- Non-randomized observational design with potential residual confounding and case-mix differences
- Generalizability outside Japan and long-term outcomes beyond registry follow-up are not fully defined
Future Directions: Develop standardized training and referral networks to reduce severe complications in low-volume centers; conduct long-term outcome studies and cost-effectiveness analyses of BPA expansion.
2. Implications of respiratory syncytial virus seasonality for the timing of passive immunisation scenarios in Latin America and the caribbean - a cross-sectional modelling study.
Using 2010–2019 surveillance from 28 countries, RSV epidemics showed south-to-north progression and year-round circulation in the tropics. Seasonally timed or year-round passive immunization strategies avert 55–61% of RSV-ALRI in infants at 80% coverage, with combined maternal vaccine plus long-acting monoclonal antibody performing well in subtropical settings.
Impact: This study translates regional seasonality into actionable immunization windows, quantifying the preventable burden and informing policy on deploying maternal vaccination and long-acting antibodies.
Clinical Implications: Optimize timing of maternal RSV vaccines and long-acting monoclonal antibodies by climate zone: seasonal campaigns in temperate zones, year-round programs in tropics, and combined strategies in subtropics to maximize infant protection.
Key Findings
- 317,951 RSV-positive samples (12.6% positivity) were reported across 28 countries (2010–2019), with year-round epidemics in tropics and seasonal peaks progressing south-to-north.
- At 80% coverage, long-acting monoclonal antibodies could avert 61.3% (temperate exemplar) and 55% (tropical exemplar) of RSV-ALRI in infants <12 months.
- Combined maternal vaccination plus long-acting mAb in subtropical settings averted 57.3% of RSV-ALRI; year-round campaigns are preferred in the tropics.
Methodological Strengths
- Region-specific seasonality characterization using multi-country surveillance over a decade
- Scenario modeling that incorporates protection duration, uptake, and varied implementation windows
Limitations
- Model-based estimates depend on assumptions about efficacy, coverage, and duration, which may vary by setting
- Surveillance heterogeneity and under-ascertainment can affect seasonality and burden estimates
Future Directions: Prospective evaluation of real-world implementation timing, integration with maternal services, and head-to-head comparisons of seasonal versus year-round strategies across climate zones.
3. Adjunctive Corticosteroid Use and Clinical Outcomes in Non-HIV Pneumocystis jirovecii Pneumonia.
In 375 non-HIV PCP patients requiring oxygen, higher cumulative corticosteroid dosing over 21 days was associated with increased 90-day mortality (HR 1.01 per 100 mg prednisone-equivalent) without benefits on intubation risk or liberation from advanced respiratory support.
Impact: By modeling corticosteroid exposure as a continuous, time-varying dose, this study challenges common extrapolation from HIV-PCP and provides nuanced evidence that higher cumulative dosing may be harmful in non-HIV PCP.
Clinical Implications: Avoid escalating cumulative corticosteroid doses beyond trial-tested regimens in non-HIV PCP; prioritize antimicrobial therapy and supportive care while awaiting randomized evidence to refine steroid use.
Key Findings
- Higher cumulative corticosteroid dose over 21 days increased 90-day mortality (HR 1.01 per 100 mg prednisone-equivalent; 95% CI 1.00–1.02).
- No association between steroid exposure and risk of intubation or faster liberation from advanced respiratory support.
- 93.6% received steroids; overall 90-day mortality was 44%, with high ICU utilization (56%).
Methodological Strengths
- Marginal structural models with inverse probability weighting to address time-varying confounding
- Multicenter cohort with explicit dose–response modeling of corticosteroid exposure
Limitations
- Retrospective design with potential residual confounding and exposure misclassification
- Lack of standardized steroid protocols limits inference on optimal dosing regimens
Future Directions: Randomized trials comparing steroid dosing strategies in non-HIV PCP and mechanistic studies to identify subgroups that may benefit from adjunctive steroids.